New Treatment for CMS

COLUMBUS, Ohio (Ivanhoe Newswire) — It’s called congenital myasthenic syndrome, or CMS. CMS causes muscle weakness and fatigue. It is often difficult to diagnose, and tough to treat. Now, researchers are testing a new treatment designed to give patients their lives back.

Thirty-seven year old Elaine Whited steers her two sons toward afterschool snacks and homework. It’s a relief now, to keep up with their daily routines.

“Why would I not want to take care of my kids? And I couldn’t.” Whited explained.

Just two years ago, simple things like cleaning up after a meal or getting dressed, were a challenge.

“I started having to brush my hair with my head over the side of the bed because I couldn’t lift my arms up to do it.” Whited told Ivanhoe.

Elaine saw multiple doctors and nobody could tell her what was wrong, until she met Stanley Iyadurai. The neuromuscular expert says the symptoms of CMS can be very subtle, making it tough to pick up.

Stanley Iyadurai, PhD, MD, a neurologist and neuromuscular medicine specialist at The Ohio State University Wexner Medical Center in Columbus, Ohio told Ivanhoe, “What makes this different is in the setting of fatigue, they may also have eyelid drooping.”

“The reason he noticed it first is I have this lazy eye. And I’ve had it my whole life.” Whited said.

Doctor’s prescribed medication, which helped with some of Elaine’s symptoms. But now researchers are testing a new drug for CMS, Amifampridine Phosphate.

“We expect their eyelid droop to become normal, their speech to become completely normal, their swallowing difficulties to go away and the fatigue gets better.” Dr. Iyadurai explained.

Dr. Iyadurai cautions the drug may not be effective for all CMS patients. Researchers say the new drug is in phase three clinical trial; the step before the FDA considers it for approval. Researchers say this same drug would also be effective in treating another rare neuromuscular disease called LEMS.

BACKGROUND: Congenital Myasthenic Syndrome is usually an inherited disease and result of a defective gene. There are different variations, but it is generally characterized by fatigue or weakness resulting in problems at the neuromuscular junction, where muscle and nerve cells meet. Symptoms vary from mild to severe, but generally include weakness, fatigue, and droopy eyelids. The earlier the onset of the disease, the more severe the symptoms may be. Presynaptic CMS or CMS with episodic apnea causes weakness in the muscles controlling the eyes. It also causes nerve weakness in the brain stem which makes it difficult to talk, chew, swallow and hold up the head, and episodes of apnea (a temporary cease of breathing). Postsynaptic CMS can cause severe weakness, feeding and respiratory problems in infants, but childhood and adult cases don’t usually interfere with daily lives other than droopy eyelids and fatigue. Finally Synaptic CMS can cause extreme weakness difficulties feeding and respiratory issues. The weakness may result in delayed milestones, and often lead to scoliosis and reduced mobility.
(Source: https://www.mda.org/disease/congenital-myasthenic-syndromes/signs-and-symptoms)

TREATMENT: Currently there is no cure for CMS, only treatment options. It is important to know that while one type of medication may help a certain subtype of CMS, another may not help or sometimes can even do harm. Since it isn’t an autoimmune disease, it doesn’t respond to immunosuppressants or other treatments targeting the immune system. Cholinesterase inhibitors boost levels of ACh, which is a chemical necessary for proper muscle function. Sometimes these drugs can cause diarrhea, excessive salivating, or abdominal cramps. To minimize these side effects, the doctor may lower the dose of cholinesterase inhibitors or prescribe atropine, which blocks the ACh receptors on nerve cells.

NEW TECHNOLOGY: While CMS treatments vary and results may not be the same for all patients, a new drug is being tested called Amifampridine Phosphate. It is being investigated in phase three clinical trials currently, the step just before FDA approval. Researchers say this drug may also be effective in treating another rare neuromuscular disease called LEMS. Amifampridine phosphate is a potassium channel inhibitor that is designed to cause greater stimulation of muscles by prolonging nerve signals. This helps counteract the muscle weakness in people with CMS, which could help to calm symptoms such as eyelid dropping, speech slurring, swallowing issues and general movement.

If this story or any other Ivanhoe story has impacted your life or prompted you or someone you know to seek or change treatments, please let us know by contacting Marjorie Bekaert Thomas at mthomas@ivanhoe.com

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